This invention relates to a dynamically variable oscillating adjustment assembly. More specifically, this invention relates to a dynamically variable adjustment assembly wherein stroke amplitude and a center position of oscillating movement may be selectively adjusted while the mechanism is oscillating.
In various oscillating stroke mechanisms it is desirable to adjust or vary a central position and stroke amplitude of the oscillating device. Presently known techniques require stopping a machine and relevant oscillation mechanism, making adjustments to eccentrics, linkages, arms, and the like and restarting the machine. The foregoing steps are repeated for as many iterations as are necessary to achieve the desired adjustment. The present invention does not require stopping the mechanism motion in order to make necessary adjustments. In this connection, adjustment is facilely achieved with the instant invention by dialing in a desired stroke and position while the machine is running.
While this invention is envisioned as having application in a number of environments, one context which is of particular interest is in the finishing or polishing of contact lenses. Contact lenses are initially formed with a substantially completed prescriptive value; however, a final polishing and finishing operation may be performed in order to ensure a smooth lens surface without aberrations, etc.
A lens polishing operation entails mounting a lens block carrying a contact lens upon a spindle within a polishing machine where the spindle is rapidly rotated about a central longitudinal axis of the lens. At the same time a polishing pad is mounted above the rapidly spinning lens and is oscillated back and forth over the lens as the lens spins. The above procedure has been found to provide sufficient variety of motion so as to avoid unwanted ridges or aberrations on the contact lens as finishing is achieved.
In lens polishing it is often desirable to change the position or stroke of oscillation of the polishing pad with respect to the contact lens. In the past when this adjustment of polishing pad position and amplitude of oscillation was desired, the polishing machine had to be stopped and various eccentrics and other arms were mechanically adjusted in length and then the machine was started again. Such down-time in any given machine which may simultaneously polish eight or more lenses is undesirable and it would be highly beneficial in the lens finishing art to be able to make position and stroke oscillation adjustments as a polishing machine is running.